Crush dressing mechanism



Sept. 22, 1953 CRUSH DRESSING MECHANISM Original Filed July 26, 1946 E. V. FLANDERS ETAL 4 Sheets-Sheet 1 4 Sheets-Sheet 2 J 27 v jar/0% /Z Jar MW I i JW Sept. 22, 1953 E. v. FLANDERS ETAL CRUSH DRESSING MECHANISM Original Filed July 26, 1946 Sept. 22, 1953 E. v. FLANDERS Erin. ,6

CRUSH DRESSING MECHANISM Original Filed July 26, 1946 4 Sheets-Sheet 3 Sept. 22, .1953 'E. v. FLANDERS ETAL CRUSH DRESSING MECHANISM Original Filed July 26, 194

4 Sheets-Sheet 4 Patented Sept. 22, 1953 CRUSH. DRESSING MECHANISM Ernest V. Flanders and Carroll H. Drury, Springfield, Vt, assignors to Jones & Lamson Machine Company, Springfield; Vt., a corporation of Vermont Continuation o application Serial No. 686,470,

July 26, 1946.

1953, Serial No. 332,706

11 Claims. (CL. 512-) This invention relates to mechanism for crush dressing grinding wheels. 6

One object of the invention is to provide mechanism interchangeable with diamond dressing mechanism in a grinding machine.

A further object is to providehyd'raulic pressure means for forcing the crushing roll against the grinding-wheel, togetherwith means for advanci'ng the crushing roll independently of the fluid pressure means to compensate for wheel wear and crushing.

Still another object is to provide for stopping the rotation of the wheel for the presentation thereto of the crushing roll, after which the wheel is rotated in either direction desired at a relatively slow crushing speed.

A further object is to provide for automatic resumption of full speed grinding wheel rotation in grinding direction after crushing has proceeded to the desiredextent.

Still another object is to provide means whereby the crushing pressure may be adjusted to suit the width and profile of the grinding wheel and other conditions.

Still another object is to provide an improved cycle of control of the crushing roll and grinding wheel.

For a complete understanding of this invention, reference may be had to the accompanying. drawings in which:

Figure 1' is a, longitudinal vertical sectional View through the. crushing mechanism and related parts, a portion of the grinding wheel being shown.

Figure 2 is a rear end elevation of the same.

Figure 3 is a detail.v sectional view on line 3-3 of Figure l.

Figure is a detail sectional view to a larger scale on line t-:l of Figure 2.

Figure 5 is adetail sectional view to a larger scale online 5-5 of Figure 6. 7

Figure 6 is a detail sectional view on line 8-6 of Figure 1 Figure 7 is a View similar to a portion of Figure 6 but showing a modified construction.

Figure 8 is a fragmentary end elevation of the crusher roll mounting of Figure '7.

Figure 9 is a fragmentary sectional view illustrating corresponding faces of the grinding wheel and the crushing roll.

Figure 10' is a wiring diagram of the grinding wheel drive and crushing mechanism, illustrating the cycle of operations.

This invention is shown asapplied' to a thread grinding machine of the type shown in Flanders This application. January 22,

'2 Patent No. $184,011, granted December 19, 1939, and the crush truing mechanism of this invention is arranged to be interchangeable with the diamond truing mechanism shown in that Flanders patent.

At t is shown the cradle having a forward portion which partially surrounds the grinding Wheel 2 rearwardly from the work. This cradle has a tubular extension 3 within which the truing mechanism is placed. In accordance with this invention this truing mechanism comprises a cylindrical casing 4 arranged to be inserted within the tubular extension 3 as far as permitted by the engagement of a circular flange 5 on the casing & against the rear end of the extension 3. These parts may be secured together with capacity for limited angular adjustment'by screw and slot connections This casing l contains orsupports the wheel crushing mechanism. This casing is provided with a pair of transverse partitions ii and l provided with bushings 8 for slidably mounting a ram 9. The forward end of this ram is provided with a head it within which is journaled the crushing roll H, and when this crushing roll is'intended to crush the grinding wheel 2 to multiple rib form, as for thread grinding', it will be provided with complemental ribs. The partition 6 except for the opening where the bushing S is positioned, is solid and the rear end portion of the head is connected to the forward end of the bushing as by a flexible diaphragm l2, thereby to prevent, detritus from the wheel from entering back of the partition 6.

The rear end of the ram 9 is hollow and has fixed thereto a nut M threaded for the receptime of the forward end of a threaded rod 55. This rod 15 is the piston rod of a piston 56 which slidable within a hydraulic cylinder H. The piston rod 15 extends through the head E8 of this cylinder through a packing gland l9, and has a splined portion on which is mounted a correspondingly splined gear 20. This gear is coupled through an idler 2i, journaled on a stub shaft 22, to a gear 23 carried by a shaft 2.45 cou pled as through the coupling elements 25 and 26 with a shaft 21. This shaft 2? forms a portion of the wheel feed mechanism and corresponds to the shaft 5-! of the Flanders Patent No. 2,184,011. This shaft has a threaded portion 26 threaded through a. lug 29 upstanding from a portion 30 of the grinding machine frame and it also has fixed thereto a gear 3i meshing with long gear 32 carried by shaft 33, which, in turn, has meshing therewith a gear 3%- carried by a shaft 35. This corresponds to the shaft 45 of Flanders Eatent No. 2,184,011, and this is turned time with the traverse of the work for a predetermined angular distance which allows the entire truing mechanism to be advanced toward the grinding wheel by the amount axial motion of the shaft 21. This provides for feed of the truing mechanism to provide for wheel wear and truing in the well known manner. It will be noted that when this shaft 35 is turned, the shaft 55 is also turned, the turning of this shaft i5 advancing the ram 9 with relation to the piston l6 by the amount of advance of the truing mechanism, and this is entirely independent of the axial position of the piston 55 within the hydraulic cylinder H.

The hydraulic cylinder I1 with'its piston 16 provides for applying crushing pressure of the dressing roll H against the grinding wheel, this pressure being exerted first while the grinding wheel is stationary and then during a relatively slow rotation of the grinding wheel by means which will later appear, until the crushing has been effected to the desired extent.

The hydraulic pressure is derived from a pump (iii (see Figure 3) which takes oil from the interior of the casing 4 through an inlet port 4! and discharges through a pipe 32 into a valve chamber 43 (see Figure 1). This pump it is operated by a drive shaft 44 provided at its upper end with a worm wheel 95. With this worm wheel meshes a worm 46 on a horizontal shaft 41 journaled laterally in the upper portion of the casing 4 and extending outwardly therefrom at one end, as shown in Figure 3, where it is provided with a belt pulley 48 keyed thereto. This pulley t8 is connected by a drive belt it with a motor 5!] carried by the casing 4 back of the flange 5. Whenever this motor 50 is driven, fluid under pressure is delivered from the pump it through the pipe 42 to the valve chamber 33 against the forward end of a, valve 52 (see Figure 1) which is normally spring pressed forwardly as by a spring 53 reacting between its rear end and the rear wall of the casing 43. When this valve 52 is pressed rearwardly sufficiently, hydraulic pressure is delivered from forwardly of its forward face through the passage 55 past a ball check valve 58 and through passages 5? and 58 to the interior of the cylinder l! rearwardly of the piston It, thus to drive the piston 53 forwardly and press the crushing roll 5 5 against the grinding wheel.

The amount of pressure exerted against the piston it may be adjusted in accordance with the length and contour of the crushing surfaces, or for other reasons, and for this purpose there is shown in Figure 3 the rear end of the cylinder H which communicates through a passage {it with a ball valve 5!. This valve is pressed toward seating position by a slide 62 within a casing 63 and the slide is adjustably loaded by a spring 64, the outer end of which engages a head of an abutment member 65. The outer end of this member 65, is, in turn, engaged by a screw 66 threaded through a closure plug 6! for the casing 63. This valve 65 controls a discharge passage 68 leading back into the interior of the casing :3. By loading this valve 5! to the desired extent, the maximum hydraulic pressure back of the piston is may be regulated as desired.

The rear end of the cylinder [1 is also provided with a small continuously open bleeder port it (Figure 1) leading out to the interior of the casing 4, so that whenever the pump 45 stops operating, the fluid pressure leaks off from back of the piston it and permits the ram and the crush dressing tool to be retracted from the grinding wheel. This retraction is accomplished by springs 10 (Figure 6) secured at their rear ends to pins H in the rear wall "l2 of the casing 4, and extended through perforations '13 through the partition 1' and having their forward ends engaged in the heads of pins 74 secured in a clamp collar T5 surrounding and clamped to the ram 9 as by the clamping bolt '16. The collar 15, as shown, is provided with a notch 18 which takes over a guide pin 19 projecting rearwardly from the partition 6, thus preventing undesired turning of the ram 9 which would bring the .such angular adjustment of the ram 9 as may be necessary.

The rear end of the casing i is closed off by a cap 83 which is secured to the rear end of the casing 4, as by the longscrews 8! which pass through arcuate slots 82 in the cap 8%! and are threaded into the casing d. This permits limited angular adjustment of the casing 4 with reference to the cap 89, the angular positon of which is determined by sliding engagement with the guide bar 83 of the grinding machine. This cap carries the journal 22 for the idler gear 2| and also the bearing for the shaft 24. It also carries certain of the control mechanism as will later appear.

Angular adjustment of the casing 4, with respect to the extension 3 and the cap Bil to line up the crushing roll ridges with the grooves of the grinding wheel as when the wheel is inclined to the helix angleof the work, may be produced, when the screw connections of 5a and 82 are loosened, by turning a shaft 35 journaled in the cap as (see Figure 4) and provided with a squared rear end 86 for engagement with a wrench, this shaft having keyed to its inner end a pinion 5i meshing with an arcuate rack bar 83 secured to the casing l as by means of one or more screws 8%. Mating scales at and 92 on the cradle and flange 5, respectively, show the extent of such adjustment.

The control mechanism hereinbefore mentioned carried by the cap 80 comprises a pair of limit switches ISLS and l6LS between which is rockable an actuating arm H35 fixed to a rocl; shaft IN. This rock shaft lill also has depending therefrom a dog I82 which extends down forwardly of a conical abutment H15 adjustable axially on the rear portion of the splined piston rod [5. This abutment has engaged against its outer face a large diameter nut 36 threaded on a reduced diameter portion I01 of the rod 15. A set screw IE8 passing radially through the nut I06 may be employed to lock the nut in adjusted position on the rod. This abutmentlllfi is so positioned as to impinge upon the dog m2 when the crushing. roll ram approaches its desired limit of crushing position, thereby rocking the dog [92 and consequently the shaft ill? and the arm I60 inwardly, allowing the switch lfiLS to open and thereafter closing the switch EELS, while on the reverse direction of motion of the rod l5 as the ram retracts, the switch [5L6 is allowed to open, after which the switch IBLS is closed. The periphery of the nut Hi6 may be graduated to cooperate with anindex mark on the abutment [05 to indicate the position of adjustment axially of the rod I5 of the abutment 105. It will be noted that no matter what the angular position. of the rod I15 may be, this rod being turnedby angular increments with. the feed of the wheel. toward the work as. previously mentioned, the abutment is effective to operate the dog I82 in one direction. A spring lit engaging a post HI carried by the upper end. ofv the arm I09 and a fixed post H2, acts to swing the lower end of the arm Hill and the dog ["62 backwardly as far as permitted by a stop H4 carried by the upper end of the arm I which impinges against the outer face ofv the cap member 88.

Figure 7 illustrates. a modified mechanism for determining the angular adjustmentof the ram 9, It comprises a ring member !20 adapted to be clamped about the ram 9 and provided with an index at [2| which cooperates with a; datum line I22. on an extension I23 of the clamp 15 to which the retracting springs m are attached. Gn loosening the clamp 75-, the angular position of the ram, and consequently of the crushing roll, may be adjusted. This avoids the rack and gear adjustment of Figures 2 and. 4-, but it is not so accessible. This figure and Figure 8, also, show a mounting for the crusher roll which. is adjustable axially of the roll so as. to make it possible to directly aline the complemental faces of the crusher roll and grinding wheel. As shown therein. the crusher roll Ha is carried by a rotary spindle [3E3- mounted for rotation in a bearing member l3! carried by a slide I32. This slide is provided with a dovetail portion. 133 which slides in a correspondingly shaped way I34 on a bracket I35 fixed to the ram 1 and transverse to the axis of this ram so that the slide I32 may be adjusted laterally of the ram axis. Suchadjustment may be produced by turning an adjusting screw l36 journaled in. an end wall I31 of the bracket I35 and threaded into the slide l32. This arrangement permits the roll to be adjusted axially so as to. bring its peripheral ridges i 4% directly opposite to the valleys 14! of. the grinding wheel as shown best in Figure 9.

The various mechanisms of the. crush dressing structure hereinbefore described are caused to operate in a semi-automatic cycle of operations, and the switches iiiLS. and IBLS form portions of the control of this driving mechanism. The

power for the cycle is derived from. either of two sources, one comprising two lines of a threephase alternating power system, these two lines being indicated at 255. and 22! of. Figure 10. The. normally open switch I 5LS is directly across these lines and is in circuit. with a coil. 206 of. a timing switch 195. Also across the lines 290 and 2?]? is a rectifier at ISL the direct current terminals of which furnish the power source for a slow rotation of the. grinding wheel during truing. The power for normal wheel drive for grinding is taken from the direct current lines 203 and 2134,

Sequence of operation for crush dressing The wiring diagram of Figure shows the parts with the wheel motor 553 running at grinding speed, deriving energy from the direct current lines 293 and 224. The conditions are as follows: the circuit is closed from the D. C; line 253 through lead 225, coil of relay t'ICR, lead 295 through closed wheel stop switchv 20?, leads 2G8 and 289 through closed switch arm 2| ii of the relay tl'CR, leads 2 and 2| 2 to the D. C. line 294. This same closed switch 2H connects from the line 293 throughleads 205; coil 2'13 or the coolant motor switch. 2IM, lead 264, closed switch. arm 21.0, leads 2H and. 212 to the D. (3.. line: 224. Closing of. the switch 2 i M causes the coolant motor 2i-5 (which. supplies coolant to the wheel and work. in the well known'mam her) to be energized from" the D. C. line 2%, lead 205 coolant motor 215,. closed switch 21M, leads 21B and. 2 I-TI to the D. C. line. 204. Coils of relays 3-|M.| andi 3iM2 are closed, the circuit being from the: D: Cr line 283 through lead 225, coil of the relay CHM] and coil of the relay 3|M2 in. parallel with. each other, lead 22 El, closed switch 221 of the. relay 32M], lead 222, closed switch 223- of the relay 33GB, lead 224, closed switch 225 of the relay MGR, leads 226, 2H and 2l2' to D; 0. line 2554". Energization of the coils of 31M! and 3IM2 closes a circuit from the D. 0. line through the wheel motor i511 armature and series field as follows: from line 203, lead 295 to lead 221?, closed switch 228 of the relay 3IM2, lead 229, resistance control MFA, lead 232, closed switch 23! of relay 34A, lead 232, armature 2-33 of. the wheel motor I58, lead 234', closed switch 235 of the relay 32Ml, lead 236, series field 23?, leads 238 and 239, closed switch 246 of the relay KIMI, leads 2 and 2' to the D. C. line 254.

Energization of the coil of the relay 3 [FA energizes the shunt field of the wheel motor i513 from the D. C. line 203, lead 245, switch 246 of the relay 3 IFA, lead 241, shunt field 248 and lead 249 and 2|! to the line 204.

The dressing cycle When crush dressing is desired, the grinding wheel is first stopped by pressing the stop button 201. This interrupts current through the coil' of the relay Iii-CR which opens the switch llii which supplies current to the coolant motor control coil 21 3. This allows the switch 2IM. to open which permits the coolant motor 2i5 to coast't'ostop.

Deenergization of the coil of the relay 3iCR also interrupts current through the coils of the relays 3 lMi and 3 [M2 at the switch 225.

Deem-irgization of the coils of relays 3! MI and B l-M2 interrupts current flow through the motor armature 233. The shunt field 248 remains energized. The coil of the relay 3IMI being. deenergized, the switch 255 closes, which makes a closed path including the wheel motor armature 233' and the braking resistor 3R3 as follows: closed switch 255, lead 255', resistance 3l6 of SIR-C, lead 25?, resistor 3R3, lead 258, motor armature 233, lead 234, closed switch 235 of the relay 3'2'Ml, Iead236, series field 23]; leads 238 and 239, back to the closed switch 255. The wheel motor I thus stops by dynamic. braking.

Switch 2LS is closed when the truing feed mechanism is to be operated. Closing of this switch 2L8 closes a circuit through. the coils of the relays ZCR and. 32GB as follows: from direct current line 223 to leads 265 and 266, coil of the relay 32CR, lead. 261, switch 258 of the relay 56R, lead 269, closed switch 216 of the relay IBCR, leads 211 and 212, closedswitoh 2L8, leads 213 and H2 back to the D. C. line 204, this being the circuit for the relay coil 32CR. For the relay coil 2CR the circuitv is from the line 203, leads 265, 286 and 274, coil of. the relay 20R, leads 2'55, 276 and 251, closed switch. 263 of the relay 50R, lead 269, closed-switch 210 of the relay ItC-R, leads 2?! and 212, closed switch 2LS, leads 213 and M2 to theD. C. line 204.

. Energi'zation of the coil of the relay 20R starts the truing device pump motor 50 which feeds the crushing roll against the grinding wheel by closing of the switch 2'19 from D. C. line 203, lead 2'10, coil of relay 41M, lead 2'", switch 219, leads 286 and 314 back to D. C. line 204. Energization of the coil of relay 41M closes the switch 280 which starts the truing device motor from D. C. line 203, the motor 50, switch 280, lead 2'18 to D. C. line 204; The relays ZCR and 32GB are maintained energized by a holding circuit through the switch arm 285 of the relay 2CR as follows: from the D. C. line 203, leads 265 and 266, coil of the relay 320R, lead 261, closed switch 268 of the relay 50R, lead 269, closed switch 2'10 of the relay 160R, lead 2', switch 285 of the relay R, leads 2% and 212 to the D. C. line 204. This by-passes the switch 2LS which can now open without opening this circuit.

Energization of the coil of the relay 320R energizes the relays 32M! and 32M2 as follows: from D. C. line 203 to lead 205, coil of the relay 32M1 and 32M2 in parallel, leads 290, 291, closed switch 292 of the relay 31RC, lead 293, closed switch 294 of the relay 31M2, lead 295, closed switch 296 of the relay 320R, leads 29'1 and 224, closed switch 225 of the relay MGR, leads 220, 21! and 212 to the D. C. line 20%. Energization of the relays 32M'1 and 32M2 closes the switch arms 300 and 301 which permits closing of the circuit to the wheel motor armature 233 from the D. C. rectifier lines 302 and 303 upon closing of the wheel start switch 3 I 8 as will later appear.

Energization of the coil of the relay 320R closes a switch 200 which closes a circuit from the D. C. line 203 through lead 255, coil of the relay 33CR, lead 281, closed switch 280 of the relay 32GB, leads 202 and 212 to the line 204. This energizes the coil of the relay 33GB, and this, in turn, opens a switch arm 223 of this relay which breaks the circuit through the coils of relays 31M1 and 31M2 which acts to disconnect the wheel motor 150 from the D. C. lines 203 and 204.

Closing of the relay 32GB energizes the shunt coil 310 of the relay 31RC from the D. C. line 203, lead 205, coil 310 of the relay 31RC, lead 311, switch N2 of the relay 32GB. and leads 313,

314 and 312 to the D. C. line 204. This closes the switch 292 unless this is prevented by braking current flow through the series coil 316 of the relay 31RC. The rectifier is thus guarded against pumping back through the braking current of the wheel motor should the motor not be stopped. As soon as the switch 292 closes, the apparatus is conditioned for starting the grinding wheel rotation for crushing, which is started by pressing the wheel start button. The crushing roll is now pressing against the stationary grinding wheel.

The wheel start button 318 is now closed by the operator, which energizes the coil of the relay 31CR from the D. C. line 203 through lead 205, coil of the relay 310R, lead 200, closed switch 20'1', lead 200, wheel start button 318 and leads 319 and 212 to the D. C. line 204. The relay 310R is maintained closed through a holding circuit including the switch 210, the circuit being from the D. C. line 203 through lead 205, coil of the relay 31CR, lead 206, closed stop switch 201, leads 208 and 200, switch 210 of the relay 310R, leads 2!! and 212 to the D. C. line 204.

Energization of the relay 31GB energizes th coil of the relay 21M which starts the coolant motor as previously described.

Energization of the relay 35GB also energizes the coils 32M1 and 32M2 through the relays 320R, 31M2 and 3112C which connects the wheel 8 motor to the rectifier leads 302 and 303 as follows: from rectifier lead 302 through switch arm 300 of the relay 32M1, lead 325, variable resistor 326, leads 327 and 328, wheel motor armature 233, lead 258, lead 329, switch 301 of the relay 32M2 to the rectifying lead 303.

Energization of the relay 32M 1 opens the switch arm 235 which opens the circuit through the series field, leaving the shunt field energized. The wheel motor now drives the wheel at slow crushing speed and in a direction determined by the connection of the rectifier leads 302 and 303 to the rectifier. Reversing these leads, reverses the direction of crushing rotation of the grinding wheel. By driving the wheel during crushing in the reverse direction to grinding so that the contact between wheel and roll is moving downwardly, no lifting efiect on these parts is produced so that no hold down devices are necessary and clearing of the wheel from crushed particles is facilitated.

It will be noted that the wheel driving motor 150 is cut 01 from both D. C. lines 203 and 204 by opening switches 228 of the relay 31M2 and 240 of the relay 31M1. This is a safety feature which guards against D. C. line voltage stresses in the rectifier.

The constant hydraulic pressure derived from the pump 40 driven by the pump motor 50 is now applied to the crusher roll while the grinding wheel rotates at low speed and in the desired direction, and this continues crushing the grinding wheel to shape until the limit switch 1 BLS is opened by the hydraulic feed mechanism as the wheel approaches size. Opening of this switch 1516 would deenergize the coil of the relay 330R, the circuit being from the D. C. line 203 through lead 205, coil of the relay33CR, lead 335, switch 336 of the relay 330R, lead 331, switch IBLS, and leads 338 and 212 to the D. 0. line 204, except that the coil of the relay BZCR is now energized.

As the wheel reaches size, however, the micro switch IELS is engaged and closed by the feed mechanism which starts the timing device T, and during the time interval before the timing switch T closes, the entire wheel is crushed smoothly to size.

At the end of the set time, closing of the time switch T energizes the coil of the relay 160R as follows: From the D. C. line 203, through lead 265, coil of the relay R, lead 340,switch 341 of the timer T, leads 342 and 211 to the D. C. line 202. Energizing of the coil of the relay IBCR. opens the switch 2'10 of the relay 100R which breaks the circuit to the coil of the relays 2GB and 32GB.

Deenergization of the coil of the relay 20R deenergizes the coil of relay 41M, allowing the switch 200 to open and stop the truing device pump motor 50. The hydraulic pressure in the cylinder 1'1 now bleeds oil, and the springs '10 retract the crushing roll from the wheel.

Deenergization of the coil of the relay 3283 now that switch IELS is also open, deenergizes the coils of the relays 33GB, 32M! and 32M2 which disconnect the wheel motor from the rectifier.

The relay 32M1 being now deenergized, the braking resistors 332 and 3R3 are connected in series to the motor armature to stop the wheel motor 150 by dynamic braking.

The withdrawal of the crushing roll allows the switch 15LS to open and thereafter causes the switch. IBLS to be engaged and closed.

9 This deenergizes Lthe coiliof the relay 133GB which closes the switch .223 of this relay, again energizing the coils of the relays 31M! and .'3:IM2 which connect the grinding wheel motor 150 across the D. 0. lines 283 and 204 .as first described, so that the wheel motor resumes grinding speed in grindingdirection.

From the foregoing description of certain embodiments of this invention it should be evident to those skilled in the .art that various further changes and modifications might be made without departing from the spirit or scope of this invention.

We claim:

1. In combination with the rotary grinding wheel of a grinding machine, a wheel truing mechanism comprising a crushing roll, means supporting said roll on said machine 'for rotation about an axis substantially parallel to that of said wheel and for motion "toward .and from said wheel, a fluid pressure motor connected to said roll for moving said roll aganist said wheel and there holding it under pressure from said fluid, said motor having a continuously open bleeder port for the escape of fluid under pressure therefrom, means biasing said roll to a position retracted from said wheel, a source of fluid, a fluid conductor circuit between said source and motor, a pump in said conductor circuit for pumping fluid from said source to said motor, and means connected thereto for controlling the operation of said pump.

2. In combination with .a rotary grinding Wheel of a grinding machine, .a wheel timing mechanism comprising a crushing roll, means supporting said roll on said machine for rotation about an axis substantially parallel to that of said wheel and for motion toward andfrom said wh el, a f d pressure m or connected .to said roll for moving said roll against said wheel, and there holding it under pressure from said fluid, d -motor having a continuously open bleeder port for the escape of fluid under pressure therefrom, means connected thereto biasing said roll to a position retracted from said wheel, a source of flu d, a fluid conductor circuit between said source and motor, a pump in .said conductor sir cuit for pumping .fluid from said source .to said motor, and means operativelyconnected thereto for adjustably limiting the pressure of fluid in d motor- 3. In combination with a rotary grinding wheel of a grinding machine, a wheel 'truing mechanism comprising a crushing roll, means supporting said roll on said machine for rotation about.

n x s n ial y parallel o that of said wheel and for motion toward and from said wheel, a fluid pressure motor .connectedto said r ll f moving s rollagainstsaid wheel and there holding it under pressure from said fluid, said motor having a continuously open bleeder port for the escape of fluid under pressure there from, means connected thereto biasing said roll to a position retracted from said wheel, a source of fluid, a fluid conductor circuit between said means supporting said wheel for rotation, a ram mounted :for axial motion toward and from said grinding wheel, a wheel crusher roll journaled on said ram for motion by motion of said ram toward and away from the periphery of said wheel, a piston connected to said ram, a stationary'hydraulic cylinder within which said piston is slidable, means :operatively connected theretovfor forcing hydraulic fluid into said cyl inder back of said piston to force said crusher roll against said wheel, means operatively connected thereto for controlling said forcing means, said cylinder having a continuously open bleeder port for the escape of fluid from said cylinder, and means operatively connected thereto biasing said ram in a direction to retract said roll from said wheel.

5. The combination with a grinding wheel and means supporting said wheel for rotation, of a ram mountedfor axial motion toward and from said grinding wheel, a wheel crusher roll journaled on said ram for motion by motion of said ram toward and away from the periphery of said wheel, a piston connected to said ram, a stationary hydraulic cylinder within which said piston is slidable, means .operatively connected thereto :for forcing hydraulic fluid into said cylinder back of said piston to force said crusher roll against said wheel, means operatively connected thereto for controlling said forcing means, means operatively connected thereto for adjustably limiting the maximum pressure of fluid in said cylinder, said cylinder having .a continuously open bleeder .port for the escape of fluid from said cylinder, .and means operatively connected thereto biasing said rare in the direction to retractsaid roll from said wheel.

'6. The combination with the grinding wheel of a grinding machine .and means including a motor operatively connected thereto for rotating said wheel about its axis, a crushing roll mounted for motion on said machine toward and from said grinding wheel, means operatively connected thereto for moving said r011 toward and pressing it against said grinding wheel, a pair of controls for said motor selectively assoeiable therewith, one of said controls when effective causing saidmotor to rotate at fast grinding speed in grinding direction, and the other of said controls when reflective causing said motor to rotate at .slow crushing speed in crushing direction, means operatively connected to said con- 11018 a d Operator actuable to stop said motor and wheel .irom fast grinding speed, to actuate said roll moving means to press said roll against said grinding wheel while said grinding wheel is stationary :and to .select said slow wheel rotating means for operative connection to said motor, means operatively connected thereto and operator actuated to activate said slow wheel rotation crushing :roll when said roll has been moved against said wheel to a predetermined extent, to

then stop said motor and roll moving means, and to change from said slow rotating to said fast rotating motor control. I

7. The combination with the grinding wheelof a grinding machine and means including a motor operatively connected thereto for rotating said wheel about its axis, a crushing roll mounted for motion on said machine toward and from said grinding wheel, means operatively connected thereto for moving said roll toward and pressin it against said grinding wheel, a pair of controls for said motor selectively associable therewith, one of said controls when eifective causing said motor to rotate at fast grinding speed in grinding direction, and the other of said controls when effective causing said motor to rotate at slow crushing speed in the direction reverse to said grinding direction, means operatively connected to said controls and operator actuable to stop said motor and wheel from fast grinding speed, to actuate said roll moving means to press said roll against said grinding wheel while said grinding wheel is stationary and to select said slow wheel rotating means for operative connection to said motor, means operatively connected thereto and operator actuated to activate said slow wheel rotation means to rotate said wheel at slow crushing speed while said crushing roll is pressed against said wheel, means operatively connected to said control means and to said crushing roll reversing said roll movin means to withdraw said crushing roll when said roll has been moved against said wheel to a predetermined extent, to then stop said motor and roll moving means, and to change from said slow rotating to said fast rotating motor control.

8. In combination with the grinding wheel of a grinding machine, said wheel being mounted for rotation about its axis, a crushing roll mounted on said machine and movable toward and from said grinding wheel, means biasing said roll away from said grinding wheel, means operatively connected thereto for rotating said wheel in grinding direction at fast speed, means operatively connected thereto for rotating said grinding wheel in crushing direction at low speed, means operatively connected thereto for moving said roll against the action of said biasing means into crushing relation to said grinding wheel, operator actuable means operatively connected thereto for starting said wheel rotating means, means dependent upon both of said rotating means being out of operation and actuable by the operator and operatively connected thereto to actuate said roll moving means to move said roll against said grinding wheel and to condition said starting means to actuate said slow wheel driving means, and means operatively connected to said roll and automatically actuated after the starting of said slow wheel driving means when said roll reaches a predetermined crushing position to stop said roll moving means and to permit said biasing means to retract said roll from said wheel, and means operatively connected to said roll and rotating means and actuated by such retraction to a predetermined point to stop said slow wheel rotating means and start said fast wheel rotating means.

9. In combination with the grinding wheel of a grinding machine, said wheel being mounted for rotation about its axis, of a crushing roll mounted on said machine and movable toward and from said grinding wheel, means operatively connected thereto biasing said roll away from said grinding wheel, means operatively connected thereto for rotating said wheel in grinding direction at fast speed, means operatively connected thereto for rotating said grinding wheel in crushing direction at low speed, means operatively connected thereto for moving said roll against the action of said biasing means into crushing relation to said grinding wheel, operator actuable means connected thereto for starting said wheel rotating means, means dependent upon both of said rotating means being out of operation and actuable by the operator and operatively connected thereto to actuate said roll moving means'to move said roll against said grinding wheel and to condition said starting means to actuate said slow wheel driving means, and means operatively connected to said roll and automatically actuated after the starting of said slow wheel driving means when said roll reaches a predetermined crushing position to stop said roll moving means and after a dwell of predetermined time to permit said biasing means to retract said roll from said wheel, and means operatively connected to said roll and slow and fast rotating means and actuated by such retraction to a predetermined point to stop said slow wheel rotating means and start said fast Wheel rotating means.

10. In combination with the grindingiwheel of a grinding machine, said wheel being mounted for rotation about its axis, of a crushing roll mounted on said machine and movable toward and from said grinding wheel, means operatively connected thereto biasing said crushing roll to retracted position away from said grinding wheel, an electric motor for rotating said wheel, a pair of actuating circuits for said motor, one of said circuits when energized rotating said motor in grinding direction at a fast grinding speed, the other of said circuits when energized rotating said motor in crushing direction at slow speed, a manual switch operatively connected thereto for energizing selectively one or the other of said circuits, a second motor connected thereto and actuable to move said roll from retracted position toward said wheel, control means for said second motor conditioned by the deenergization of both of said circuits to energize said second motor to move said roll against said wheel, said manual switch then being actuable to energize the other of said circuits to cause slow rotation of said wheel in crushing direction, means operatively connected to said roll and second motor and actuable by the motion of said roll to a predetermined point to deenergize said second motor and allow said biasing means to retract said roll, and means operatively connected to said roll and circuits and actuated by the retraction of said roll to a predetermined point to deenergize said other circuit and to energize said one circuit to thereby cause said grinding wheel to rotate at high speed in grinding direction.

11. In combination with the grinding wheel of a grinding machine, said wheel being mounted for rotation about its axis, of a crushing roll mounted on said machine and movable toward and from said grinding wheel, means biasing said crushing roll to retracted position away from said grinding Wheel, an electric motor connected thereto for rotating said wheel, a pair of actuating circuits for said motor, one of said circuits when energized rotating said motor in grinding direction at a fast grinding speed, the other of said circuits when energized rotating said motor in crushing direction at slow speed, a manual switch operatively related to said circuits for energizing one or the other of said circuits, a second motor connected to said roll and actuable to move said roll from retracted position toward said wheel, control means for said second motor conditioned by the deenergization of both of said circuits to energize said second motor to move said roll against said Wheel, said manual switch then being actuable to energize the other of said circuits to cause slow rotation of said wheel in crushing direction, means operatively connected thereto and actuable by the motion of said roll to a predetermined point to stop the motion of said crushing roll and after a predetermined time interval to deenergize said second motor and allow said biasing means to retract said roll, and means operatively connected to said roll and circuits and actuated by the retraction of said roll to a predetermined point to deenergize said other circuit and to energize said one circuit to thereby cause said grinding wheel to rotate at high speed in grinding direction.

ERNEST V. FLANDERS.

CARROLL H. DRURY.

Name Date Number Bayton May 5, 1931 Number 15 Number Name Date Sinderson June 12, 1934 Haas Oct. 9, 1934 Caster 2 Aug. 6, 1935 McIlvried Dec. 14, 1939 Flygare Apr. 22, 1941 Wickman June 9, 1942 Staples July 28, 1942 Polk Sept. 25, 1945 Rickenmann July 1, 1947 Wilson July 21, 1949 Hopkins June 24, 1952 FOREIGN PATENTS Country Date Great Britain Feb. 4, 1889 

